Electronic timepiece

ABSTRACT

An electronic timepiece which includes a time .[.reference.]. .Iadd.base .Iaddend.signal generator, which generates a signal which is used to count time, and is compensated in its frequency in order to have the predetermined frequency value regardless of variations in ambient temperature.

BACKGROUND OF THE INVENTION

This invention relates to an electronic timepiece including a system forcompensating for the variation in a frequency of a time .[.reference.]..Iadd.base .Iaddend.signal with a temperature by using a temperaturesignal generator. The electronic timepiece includes a time.[.reference.]. .Iadd.base .Iaddend.signal generator and means forforming a time .[.count.]. unit signal from the time .[.reference.]..Iadd.base .Iaddend.signal. A .[.time counting mechanism.]..Iadd.timekeeping means .Iaddend.is provided for keeping a time by usingthe time .[.count.]. unit signal and a time display .[.mechanism.]..Iadd.device .Iaddend.is provided for displaying the time kept in the.[.time counting mechanism.]. .Iadd.timekeeping means.Iaddend..

The frequency of a time .[.reference.]. .Iadd.base .Iaddend.signalshould essentially be kept in the restricted range even when thetemperature of the surroundings of the timepiece is varied.

The specific resonance frequency must be changed with the externaltemperature even in a crystal oscillator which is used as a referenceoscillator for a time .[.reference.]. .Iadd.base .Iaddend.signalgenerator used in high accuracy timepieces.

In order to overcome the problems of variations in the resonancefrequency, the prior art includes several approaches. For example, withmeasurement equipment, a time .[.reference.]. .Iadd.base .Iaddend.signalgenerator is placed in a constant temperature vessel. With anotherapproach, the frequency of an output is maintained by counter-balancingthe thermal characteristics of the crystal oscillator to thetemperature-capacity characteristic of a temperature sensing elementthereby changing continuously the capacity of the time .[.reference.]..Iadd.base .Iaddend.signal generator.

The first prior art approach has problems in that large amounts ofelectric power are consumed and a large space is required. Furthermore,with the second approach, it is difficult to find a temperaturecompensating element which has a temperature-capacity characteristiccorresponding to that of the reference oscillator which is somewhatcomplex. In addition many types of temperature compensating elements donot have sufficient durability and stability and there are difficultiesin forming an integrated circuit of the temperature compensating system.

SUMMARY OF THE INVENTION

A primary object of this invention is to provide an electronic timepiecewith a highly accurate, reliable and compact temperature compensatingsystem which is capable of maintaining the accuracy of the frequency ofthe output of the time .[.reference.]. .Iadd.base .Iaddend.signalgenerator even in various temperature conditions. The system is alsocapable of obtaining a temperature compensated output signal which isaccurate from the time count unit signal generator and of performingstepping control of the .[.time counting mechanism.]. .Iadd.timekeepingmeans .Iaddend.which is equivalent to the control of the time countingmechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the system which compensates bytransducing the output of the temperature signal generator bytemperature compensating signal generator;

FIG. 2 is a block diagram showing the system which produces a signal bycomposing the outputs of the temperature signal generator, time.[.reference.]. .Iadd.base .Iaddend.signal generator and time.[.count.]. unit signal generator at the temperature compensating signalgenerator;

FIG. 3 shows a block diagram of the system in which the output of thetemperature signal generator is used directly as a compensating signal;

FIGS. 4(A), 4(B) and 4(C) show examples of the oscillators as thetemperature signal generators, respectively, FIGS. 4(D), 4(E) and 4(F)show filter circuits used in the oscillators shown in FIGS. 4(A), 4(B)and 4(C), respectively, and FIGS. 4(G) and 4(H) show examples of thecomposite elements;

FIGS. 5(A) and 5(B) show circuits for performing frequency addition;

FIG. 6 is a diagram of a frequency subtracting circuit;

FIG. 7 shows a functional block diagram of the electronic timepiecehaving the temperature compensating .[.mechanism.]. .Iadd.circuit.Iaddend. comprising the temperature sensing oscillator and frequencyadding means coupled therewith;

FIG. 8 is a functional block diagram of the electronic timepiece havingmeans for compensating the temperature-frequency characteristics of thetime reference signal by using the information relating to thetemperature intermittently measured and to the data stored in thememory;

FIG. 9 is a block diagram schematically showing the structure of theelectronic timepiece;

FIG. 10 is a perspective view showing two crystal vibrator elementsenclosed in a common casing;

FIG. 11 is a functional block diagram of the electronic timepieceincluding means for compensating the variation in frequency of the timereference signal with the temperature by using two oscillation obtainedfrom the reference oscillator which have different modes from oneanother.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2, the following reference numerals designatethe following circuit elements: 11 designates a time .[.reference.]..Iadd.base .Iaddend.signal generator; 12, a time .[.count.]. unit signalgenerator; 13, a .[.time counting mechanism.]. .Iadd.timekeeping means.Iaddend.for keeping a time by using a time .[.count.]. unit signal; 14,a .[.mechanism.]. .Iadd.display means .Iaddend.for displaying the kepttime; 15, a temperature signal generator; and 16, a temperaturecompensating signal generator, respectively.

The temperature signal generator 15 comprises an oscillator having atemperature sensing ability and .[.the.]. .Iadd.a .Iaddend.predeterminedtemperature-frequency characteristics. The .Iadd.output.Iaddend.frequency .[.changing rate.]. of the .[.temperature-frequencycharacteristics thereof are.]. .Iadd.temperature signal generator 15 is.Iaddend.generally larger than that of the time .[.reference.]..Iadd.base .Iaddend.signal generator 11.

The output of the temperature signal generator 15 has a large rate ofvariation in its temperature-frequency characteristics so that theambient temperature can easily be detected by measuring the frequencyand, accordingly it can be considered that the output of the temperaturesignal generator 15 is to be the temperature signal. In FIG. 1 thesignal transfer system is omitted, but it is necessary to obtain thefrequency or time signal used as the standard in order to measure thefrequency or periodic time. The signal from the .[.time countingmechanism.]. .Iadd.timekeeping means .Iaddend.13 or the temperaturecompensated time reference signal in the .[.mechanism.]. .Iadd.circuit.Iaddend.13 is useful as the basis of the frequency measurement.

For example, if the rate of frequency variation with temperature of thecrystal oscillator is approximately 10⁻⁵ and that of the output of thetemperature signal generator 15 is approximately 10⁻³, then thefrequency of the output of the temperature signal generator 15 can bemeasured with the smaller error by using the resonance frequency as thebasis. Alternatively, a signal from the separate crystal oscillator orsignal transmitted with an electric wave can be used as the basis.

In FIG. 1, the output of the temperature signal generator 15 is suppliedto the temperature compensating signal generator 16 as a frequencysignal having the predetermined temperature characteristics.

The temperature compensating signal generator 16 acts to convert thesignal from the temperature signal generator 15 into a signal in.[.the.]. .Iadd.a .Iaddend.form .[.of compensating.]. .Iadd.which can beused to compensate for .Iaddend.the temperature characteristics of theoutput frequency of the time .[.reference.]. .Iadd.base .Iaddend.signalgenerator 11 in accordance with the frequency of the temperature signaland to send it to at least one of the time .[.reference.]. .Iadd.base.Iaddend.signal generator 11, time .[.count.]. unit signal generator 12and .[.time counting mechanism.]. .Iadd.timekeeping means .Iaddend.13.

In the embodiment of FIG. 2, a temperature compensating signal isobtained as either a frequency corresponding to the difference betweenthe frequency of the output from at least one of the following circuits:a time .[.reference.]. .Iadd.base .Iaddend.signal generator 21, a time.[.counting.]. unit signal generator 22 or time .[.counting mechanism.]..Iadd.timekeeping means .Iaddend.23 and the frequency the output from atemperature signal generator 25 by mixing the signals in a temperaturecompensating signal generator 26, or a number given by using the lastfigure of the number and the figures near the last figure which areobtained by counting the number of pulses of the output from thetemperature signal generator within the unit time determined by the time.[.reference.]. .Iadd.base .Iaddend.signal.

The above method in which the difference of the frequency values is usedand the method in which the end of the numbers is taken by the overflowof a counter improve analysing ability in temperature detection.

The signal prepared by one of the methods set forth above is convertedinto a signal which can compensate the temperature characteristics ofthe output frequency of the time .[.reference.]. .Iadd.base.Iaddend.signal generator 21 and is sent to at least one the followingcircuits: the time .[.reference.]. .Iadd.base .Iaddend.signal generator21, time .[.count.]. unit signal generator 22 or the .[.time countingmechanism.]. .Iadd.timekeeping means .Iaddend.23 as in the case ofFIG. 1. The reference numeral 24 denotes a time display .[.mechanism.].means.

FIG. 3 shows a block diagram of a system according to this inventionsimilar to those shown in FIGS. 1 and 2 with the exception that thetemperature compensating signal generator is omitted. In the system thetemperature characteristics of the output frequency of a time.[.reference.]. .Iadd.base .Iaddend.signal generator 31 is compensatedby sending the output frequency of a temperature signal generator 35 toat least one of the following circuits: a time .[.reference.]..Iadd.base .Iaddend.signal generator 31, a time .[.count.]. unit signalgenerator 32 and a .[.time counting mechanism.]. .Iadd.timekeeping means.Iaddend.33. The reference numeral 34 indicates a time display.[.mechanism.]. .Iadd.means.Iaddend..

FIG. 4(A) illustrates a temperature signal generating system using thecombination of an amplifier having a positive amplifying rate and a.Iadd.temperature sensing .Iaddend.band-pass filter and FIG. 4(D)discloses a filter including a band-pass filter, resistors andcondencers.

The filter may be one of those having a coil or a mechanical resonanceelement.Iadd., .Iaddend.such as a ceramic filter .[.and anelectricmechanical transducer.]..Iadd., having an electromechanicaltransducing function.Iaddend.. FIG. 4(B) shows an oscillator having anoscillating frequency of about two times the shift time and includes anamplifier having a negative amplifying rate and a .Iadd.variable phase.Iaddend.shifting element. FIG. 4(E) illustrates a circuit of a low-passfilter.

FIG. 4(C) shows an oscillator having a positive feed back amplifieracting as a tuning amplifier which can eliminate the components havingthe specified frequency and is given a negative feed back at the otherfrequency than the above by means of a filter, such as the filter of thecircuit shown in FIG. 4(F).

Of course, with of the oscillators shown in FIGS. 4(A), 4(B) and 4(C)the oscillating condition should be satisfied.

If an oscillator having a larger variation rate in temperature-frequencycharacteristics is intended to be obtained, one or more elements whichdetermine the resonance frequency of the oscillator shown in FIGS. 4(A),4(B) or 4(C), such as a resistor, condenser or .[.reactance.]..Iadd.inductor.Iaddend., may be replaced with an element which variesits characteristics with temperature. For example, when one of theresistors is replaced with a thermistor or posistor, an oscillatoracting as a temperature signal generator will be constructed.Furthermore, if one of the resistors is replaced with a variableresistor the temperature characteristics may be adjusted. This is alsotrue for the replacement of capacitance.

In the systems shown in FIGS. 4(D), 4(E) and 4(F) composite elementssuch as a distribution delay element shown in FIG. 4(G) or.[.distribution.]. .Iadd.band.Iaddend.-cut filter shown in FIG. 4(H) maybe used singly or in combination with an element having a temperaturedetecting ability. Alternatively, it is possible to use digital delaymechanism or filter mechanism including a logical circuit.

Circuits performing addition and subtraction of frequency are shown inFIGS. 5 and 6, respectively.

FIG. 5(A) shows an exclusive-OR gate or a logical not circuit which canadd precisely two signals having frequencies of (f₁) and (f₂),respectively, unless the edges of the signals overlap with each other.

Error encountered upon addition would in probability be very small inthe ratio to the signals to be added and is therefore negligible.

The circuit shown in FIG. 5b acts to add two signals having frequencyvalues 2f₁ and f₂ after reforming the wave form and arrangement inconnection with the phase by a logic circuit. The circuit can improvethe accuracy of addition in comparison with that shown in FIG. 5(A) dueto the .[.settlement of the phase of the added signals by.]..Iadd.presence of .Iaddend.the logic circuit.

FIG. 6 shows a .Iadd.frequency difference detection .Iaddend.circuit forobtaining a difference signal .[.f₂ -f₁ .]. .Iadd.f₁ -f₂ .Iaddend.fromtwo signals having frequency values of f₁ and f₂, respectively. Thedifference signal .[.f₂ -f₁ can also be.]. .Iadd.f₁ -F₂ is.Iaddend.obtained by counting the frequency values f₁ and f₂ in .[.acounter separately.]. .Iadd.separate counters .Iaddend.and then takingthe difference between two counted values at .[.the.]. .Iadd.a.Iaddend.desired time. In this case the information on the frequencydifference will be obtained at .[.a constant timing.]. .Iadd.certaintimes .Iaddend.so that it is .[.needed.]. .Iadd.necessary .Iaddend.tomake the information continuous .[.through.]. .Iadd.by using .Iaddend.amemory device if the difference is required continuously.

Alternatively, .[.the.]. .Iadd.an .Iaddend.output signal .Iadd.from thecircuit of FIG. 6 .Iaddend.may be obtained .[.at.]. each time thedifference in a counter reaches .[.to the.]. .Iadd.a.Iaddend.predetermined value.

In a simpler manner, the difference value or integrated value thereofcan be obtained by using an updown counter which is so operated that onesignal is used to up count and the other signal to down count, with thecounted value being read out by changing over or resetting the counter.A similar value can also be obtained by using an up-counter and byreading out or resetting the counter at constant intervals. For example,the frequency difference in the order of 1×10³ between two signalshaving frequency values of f₁ and f₂ may be obtained by reading out thecounted value of the frequency f₁ every time when the counted valuereaches 1,000 or 10,000. Counters having a small capacity can be useddue to the fact that the difference value appears as the end of thecounted number, which enables overflowing of the higher figures.

FIG. 7 shows an electronic timepiece having a temperature compensating.[.mechanism.]. .Iadd.system .Iaddend.for a time .[.reference.]..Iadd.base .Iaddend.signal generator composed of a temperature signalgenerator and a frequency counter and a divider connecting thereto,which comprises a crystal oscillator 71 as a time .[.reference.]..Iadd.base .Iaddend.signal generator, .[.a frequency counter.]. .Iadd.analgebraical adding circuit such as EX-OR gate, .Iaddend.72, anoscillator 73 as a temperature signal generator, a time .[.count.]. unitsignal generator 74, a .[.time counting mechanism.]. .Iadd.timekeepingmeans .Iaddend.75, a time display .[.mechanism.]. .Iadd.means.Iaddend.76, an operating mechanism 77 and dividers 78.

The system is composed in the form of a C/MOS-IC or a composite circuitof C/MOS-IC and other electronic parts, the ratio between thetemperature coefficients of the respective oscillators 71 and 73 beinglarger than 1.

The outputs of the oscillators 71 and 73 are subjected to frequencydivision in the respective dividers 78 and .[.to the addition offrequency.]. .Iadd.the outputs of the dividers are algebraically added.Iaddend.in the .[.counter.]. .Iadd.EX-OR gate .Iaddend.72 so as to.[.count as.]. .Iadd.form .Iaddend.the minimum unit of the time count inthe time count unit signal generator 74. The information in thegenerator 74 is displayed on the display .[.mechanism.]. means 76 as akept time.

The .Iadd.output of the .Iaddend.oscillator 73 .[.acts to control theoscillation.]. .Iadd.is controlled .Iaddend.by the output of the control.[.mechanism.]. .Iadd.unit .Iaddend.79 .[.corresponding to the.]..Iadd.which in turn is controlled by .Iaddend.signals from the .[.timecounting mechanism.]. .Iadd.timekeeping means .Iaddend.75 and the time.[.count.]. unit signal generator 74.

The control .[.mechanism 74.]. .Iadd.unit 79 .Iaddend.is provided .[.foreliminating the increase of the consumed.]. .Iadd.to reduce the.Iaddend.electric power .[.by the action of the oscillator 73 and forcontrolling the scale of.]. .Iadd.which would otherwise be consumed by.Iaddend. the temperature compensating operation .[.or the timing.].,but it is in some cases unnecessary.

Referring now to FIG. 8, there is shown a system for .[.eliminating theincrease of the consumed.]. .Iadd.reducing the .Iaddend.electric power.Iadd.which would otherwise be consumed .Iaddend.by .[.the action of.].the oscillator 73 and for controlling the .[.scale.]. .Iadd.extent.Iaddend.of the temperature compensating operation or .Iadd.for.Iaddend.the timing .Iadd.of compensation.Iaddend., the referencenumeral 81 designates a time reference signal generator; 82, a time.[.count.]. unit signal generator; 83, a .[.time counting mechanism.]..Iadd.timekeeping means.Iaddend.; 84, a time display .[.mechanism.]..Iadd.means; .Iaddend.85, a timing control .[.mechanism.]..Iadd.unit.Iaddend.; 86, a temperature signal generator; 87, a memory;and 88, a frequency changing .[.mechanism.]. .Iadd.circuit.Iaddend..

In the embodiment set forth above, temperature signal generator 86comprises an oscillator which varies the resonance frequency in thewider range with temperature.

The timing control .[.mechanism.]. .Iadd.unit .Iaddend.85 is to controlthe start and stop operation of the temperature signal generator 86 forobtaining intermittent operation. The .[.mechanism.]. .Iadd.control unit.Iaddend.85 also acts so as to eliminate increase consumption ofelectric power by the action of the oscillator 73 and to control thescale of the temperature compensation operation or timing. The controlof the timing is done by using as an input the signals from the timecount unit signal generator 82 and the .[.time counting mechanism.]..Iadd.timekeeping means .Iaddend.83.

The temperature signal, which is obtained intermittently from thetemperature signal generator 86, is supplied to the memory 87 and storedtherein until the next .[.timing.]. .Iadd.signal is received fromgenerator 86.Iaddend.. The temperature signal stored .Iadd.in the memory.Iaddend.is then supplied to the frequency changing .[.mechanism.]..Iadd.circuit .Iaddend.88 and used for compensating the variation of thefrequency caused by the temperature characteristics of the time.[.reference.]. .Iadd.base .Iaddend.signal frequency.

FIG. 9 illustrates a block diagram of a system using a crystaloscillator as the temperature signal generator, in which the referencenumeral 91 depicts an oscillator as a time .[.reference.]. .Iadd.base.Iaddend.signal generator, and 92 an oscillator as a temperature signalgenerator wherein a crystal vibrator element 94 having a differenttemperature-frequency characteristics from that of a crystal vibratorelement 93 in the oscillator 91 is used. The oscillators 91 and 92intermittently generate outputs under the control of the .[.timecounting mechanism.]. .Iadd.timekeeping means .Iaddend.912 describedbelow.

Further to FIG. 9, the reference numeral 95 denotes a divider to dividethe oscillating frequency of the oscillator, which may be omitted, and96 temperature compensating signal generator comprising a counter 97, amemory 98 and a converter 99. The counter 97 acts to compare the outputfrom a .[.time counting mechanism.]. .Iadd.timekeeping means .Iaddend.912 described below with the output of the divider 95 or the oscillator92 when the divider 95 is omitted, in the manner, for example, that thecounter 97 counts the output frequency from the divider 95 within thepredetermined period of time in which the output from the .[.timecounting mechanism.]. .Iadd.timekeeping means .Iaddend.is supplied to.Iadd.the counter.Iaddend..

The .[.result of counting.]. .Iadd.resultant count .Iaddend.is stored inthe memory 98. The stored information in the memory 98 .[.depends on.]..Iadd.is representative of .Iaddend.the variation of temperature, thatis, the information relating to temperature. The memory 98 is controlledby the output from the .[.time counting mechanism.]. .Iadd.timekeepingmeans .Iaddend.912 so as to keep an information until the followinginformation is supplied. The converter 99 generates a temperaturecompensating signal using the output of the memory 98 in accordance withthe predetermined characteristics corresponding to thetemperature-frequency characteristics of the oscillator 91. AnExclusive-OR gate denoted by the numeral 910 adds the outputs from theoscillator 91 and the converter 99, .[.and a time count until.]..Iadd.to form a modified signal which is supplied to the time unit.Iaddend.signal generator 911 .Iadd.which .Iaddend.prepares a time.[.count.]. unit signal by dividing the output frequency of theExclusive-OR gate. Furthermore, the reference numeral 912 designates the.[.time counting mechanism.]. .Iadd.timekeeping means .Iaddend.whichprepares a signal required for display of the time using the signal fromthe time .[.count.]. unit signal generator 911, and 913 is a display.[.mechanism.]. .Iadd.means .Iaddend.capable of displaying the timeaccording to the output from the .[.time counting mechanism.]..Iadd.timekeeping means .Iaddend.912.

When the ambient temperature varies, the resonance frequency of theoscillator 91 .[.is a time reference signal generator which.]. varieswith the temperature, and the signal is supplied to the Exclusive-ORgate 910. On the other hand, the output frequency of the oscillator 92.[.as a temperature signal generator.]. also varies with temperature, sothat the output of the counter 97 .[.is different from the time beforethe ambient temperature varies.]. .Iadd.varies, .Iaddend.and the outputsignal of the memory 98 will .Iadd.also .Iaddend.vary. Accordingly, theoutput of the converter 99 which is varied is supplied to theExclusive-OR gate 910 thereby to compensate the output of the oscillator91. Namely, the output signal having a constant frequency will beobtained even when the ambient temperature varies.

FIG. 12 shows the pulse trains which exemplify the operation of theEXCLUSIVE-OR gate 910 in the circuit of FIG. 9. The gate 910 adds theoutputs from converter 99, illustrated by pulse train A, to the outputof oscillator 91, illustrated by pulse train B. The resultant pulsetrain C is applied to .[.time counting mechanism.]. .Iadd.timekeepingmeans .Iaddend. 911. As is seen in FIG. 12, there is an increase in thenumber of pulses due to coincidence of the leading edges of the pulses Aand B. The input frequency to the time count signal generator can,therefore, be kept constant in spite of temperature changes if theoutput signal frequency from the oscillator 91 is added in inverseproportion to the output frequency of the converter 99.

The above embodiment shown in FIG. 9, is so arranged that the variationof the frequency with temperature of the oscillator 91 is compensatedfor by supplying to the Exclusive-OR gate 910 the signal from theconverter 99 together with the signal from the oscillator 91, but it isalso possible to construct it so as to maintain the constant oscillationfrequency of the oscillator 91 against variation of temperature bysupplying the signal from the converter 99 to the oscillator 91.

In FIG. 10 there is illustrated an assembly in which the crystalvibrator element 93 of the oscillator 91 and the crystal vibratorelement 94 of the oscillator 92 are enclosed in a casing 95. In thiscase, the temperature compensation will be performed more stably due tothe fact that both the crystal vibrator elements 93 and 94 are laid inthe equal conditions. Furthermore, the assembly can be made smaller insize and has an economical advantage, because it is necessary to use asingle casing.

FIG. 11 shows a further system embodying this invention in whichtemperature compensation is done by taking out two output signals havingdifferent vibration modes from each other which are used in the timereference signal generator and the temperature signal generator. Twokinds of modes from a reference .[.oscillator.]. .Iadd.crystal vibratorelement .Iaddend.111 are fed to a pair of .[.vibrator elements.]..Iadd.oscillators .Iaddend.112 and 113, respectively, and the oscillator113 is controlled so as to oscillate intermittently by a .[.timecounting mechanism.]. .Iadd.timekeeping means .Iaddend.116. A counter118 is controlled, similar to oscillator 113, by the .[.time countingmechanism.]. .Iadd.timekeeping means .Iaddend.116 and reset when theoutput of the oscillator 113 becomes stable, and counts the inputfrequency within the predetermined period time. The resultant countedvalue which corresponds to temperature is written in a memory 116 whichmay store the .[.written.]. information until .[.new.]. .Iadd.further.Iaddend.information is supplied. The signal converter 120 generates atemperature compensating signal using the output of the memory 119 inaccordance with the predetermined characteristics corresponding to thetemperature-frequency characteristics of the time .[.reference.]..Iadd.base .Iaddend.signal.

A frequency changing .[.mechanism.]. .Iadd.circuit .Iaddend.114, in caseof need, generates a signal used for obtaining a time count unit signalin the mechanism 115 by compensating the time reference signal from thetime reference signal generator comprising the oscillator 112 inaccordance with the signal from the time count unit signal generator 115via the time counting mechanism 116. Furthermore, the time counting.[.mechanism.]. .Iadd.circuit .Iaddend.116 keeps the time counted inaccordance with the time count unit signal generator 115, and a display.[.mechanism.]. .Iadd.means .Iaddend.117 displays the time. It ispossible to form a system in which the function of the frequencychanging .[.mechanism.]. .Iadd.circuit .Iaddend.111 is given to the timecount unit signal 115 or the time counting .[.mechanism.]. .Iadd.circuit.Iaddend.116 itself.

The counter 118 can be constructed by connecting flip-flops in severalstages if it is used in the manner of overflowing. The converter 120 maybe realized with a read-only memory (so called ROM) in which codes arewritten for obtaining compensation of the temperature characteristics ofthe reference oscillator. Alternatively, a combination of gates may beused in lieu of the ROM.

According to this invention, as described above, the changes orvariations of the time reference signal frequency with temperature canbe compensated for stably over a long period of time and the system maybe constituted as an IC without oscillators, which enables one toprovide a highly accurate electronic timepiece which is small in size.

What is claimed is:
 1. An electronic timepiece which is provided with atime reference signal having an output signal time count unit signalgenerator, a time counting mechanism and a time display mechanism, theelectronic timepiece further comprising:a temperature signal generatorfor generating a temperature signal.[.said generator.]..Iadd., saidtemperature signal generator being timed to oscillate intermittently bythe output signal of said timekeeping means and .Iaddend.including anoscillator circuit having an output different from that of said timereference signal generator, wherein the ratio of output oscillationfrequencies changes with temperature variation; means for transmittingsaid temperature signal intermittently .Iadd.in response to the outputsignal of said timekeeping means.Iaddend.; memory means for storing thetemperature signal generated by said temperature .Iadd.signal.Iaddend.generator .[.until a subsequent temperature signal is generatedand for delivering said stored temperature signal when the subsequenttemperature signal is received by the memory.]..Iadd., said memory meansbeing controlled by the output signal of said timekeeping means so as tokeep the temperature signal until a subsequent temperature signal issupplied; .Iaddend. a signal converter for generating a temperaturecompensating signal .Iadd.in response to the temperature signal storedin said memory means.Iaddend., wherein said compensating signalcompensates for the variations of the output frequency of said timereference signal generator caused by temperature variations; and a timereference signal frequency variable controller for synthesizing theoutput signal of said time reference signal generator and that of saidsignal converter by compensating for the changes of the output frequencyof said time reference signal generator caused by the temperaturevariations and for delivering a resultant signal to said time unitsignal generator.
 2. .[.The electronic timepiece of claim 1, wherein.]..Iadd.An electronic timepiece which is provided with a time base signalgenerator, having a given output signal frequency, a time unit signalgenerator, a timekeeping means coupled to the output of said time unitsignal generator and a time display means coupled to the output of saidtimekeeping means; the electronic timepiece further comprising:atemperature signal generator for generating a temperature signal,.Iaddend.said temperature signal generator .[.is.]. .Iadd.being.Iaddend.timed to oscillate intermittently by the output signal of saidtime count unit signal generator .Iadd.and including an oscillatorcircuit having an output signal of a frequency different in frequencyfrom that of said time base signal generator, wherein the outputoscillation frequency of said temperature signal generator changes withtemperature variation; means for transmitting said temperature signalintermittently in response to the output signal of said time unit signalgenerator; memory means for storing the temperature signal generated bysaid temperature signal generator until a subsequent temperature signalis generated and for delivering said stored temperature signal when thesubsequent temperature signal is received by the memory; a signalconverter for generating a temperature compensating signal in responseto the temperature signal stored in said memory means, wherein saidcompensating signal compensates for variations of the output frequencyof said time base signal generator caused by temperature variations; anda time base signal frequency variable controller for synthesizing theoutput signal of said time base signal generator and that of said signalconverter by compensating for changes of the output frequency of saidtime base signal generator caused by temperature variations and fordelivering a resultant signal to said time unit signal generator..Iaddend.
 3. .[.The electronic timepiece of claim 1, wherein.]. .Iadd.Anelectronic timepiece which is provided with a time base signalgenerator, having a given output signal frequency, a time unit signalgenerator, a timekeeping means coupled to the output of said time unitsignal generator and a time display means coupled to the output of saidtimekeeping means; the electronic timepiece further comprising:atemperature signal generator for generating a temperature signal, saidgenerator including an oscillator circuit having an output signal of afrequency different in frequency from that of said time base signalgenerator, wherein the output oscillation frequency of said temperaturesignal generator changes with temperature variation; means fortransmitting said temperature signal intermittently; memory means forstoring the temperature signal generated by said temperature signalgenerator until a subsequent temperature signal is generated and fordelivering said stored temperature signal when the subsequenttemperature signal is received by the memory; a signal converter forgenerating a temperature compensating signal in response to thetemperature signal stored in said memory means, wherein saidcompensating signal compensates for variations of the output frequencyof said time base signal generator caused by temperature variations; anda time base signal frequency variable controller for synthesizing theoutput signal of said time base signal generator and that of said signalconverter by compensating for changes of the output frequency of saidtime base signal generator caused by temperature variations and fordelivering a resultant signal to said time unit signal generator;.Iaddend. said temperature signal generator .[.is.]. .Iadd.being.Iaddend.timed to oscillate intermittently by the output signal from atiming control mechanism, which is driven by inputs from the time countunit signal generator and the time counting mechanism.Iadd.; said meansfor transmitting said temperature signal intermittently in response tothe output signal from said timing control circuit.Iaddend..
 4. Theelectronic timepiece of claim .[.1.]. .Iadd.3.Iaddend., wherein saidtime .[.reference.]. .Iadd.base .Iaddend.signal generator and saidtemperature signal generator are crystal oscillators including crystalvibrator elements, which differ from each other in frequency outputcaused by the temperature variations, .[.which results in changingfrequency ratios.]..
 5. The electronic timepiece of claim 4, wherein thevibrator elements of said crystal oscillator used as the time.[.reference.]. .Iadd.base .Iaddend.signal generator and of said crystaloscillator used as said temperature signal generator are enclosed in acommon casing.
 6. The electronic timepiece of claim .[.1.]..Iadd.3.Iaddend., wherein frequencies of two modes of oscillation arederived from a single reference vibrator element; one of the frequenciesbeing used as a reference vibrator element of said time .[.reference.]..Iadd.base .Iaddend.signal generator and the other as the referencevibrator of said temperature signal generator.
 7. The electronictimepiece of claim .[.1.]. .Iadd.3.Iaddend., wherein said temperaturecompensating signal generator includes EXCLUSIVE-OR gate which.[.intermittently.]. enables said time .[.count.]. unit signalgenerator. .Iadd.
 8. An electronic timepiece having a time base signalgenerator to provide a time base signal of given frequency and having agiven temperature-frequency characteristic, means for generating anoutput signal in response to said time base signal, a time unit signalgenerator, a timekeeping means coupled to the output of said time unitsignal generator and time display means coupled to the output of saidtimekeeping means; the electronic timepiece further comprising:atemperature signal generator for generating a temperature signal, saidtemperature signal generator including an oscillator circuit having apredetermined temperature-frequency characteristic different from thatof said time base signal generator and providing said temperature signaldifferent in frequency from said time base signal, wherein an outputoscillation frequency of said temperature signal generator changes withtemperature variation; compensating signal generating means forgenerating a compensating signal in response to said temperature signal;and algebraical adding circuit means comprising logical circuit meansfor algebraically adding a frequency of said compensating signal to afrequency of said output signal to compensate for changes in a frequencyof said time base signal caused by the temperature variations..Iaddend..Iadd.
 9. An electronic timepiece according to claim 8, inwhich said temperature signal generator comprises a temperature sensingoscillator. .Iaddend..Iadd.
 10. An electronic timepiece according toclaim 9, in which said temperature sensing oscillator comprises atemperature sensing filter circuit and an amplifier connected thereto..Iaddend..Iadd.
 11. An electronic timepiece according to claim 10, inwhich temperature sensing filter circuit comprises a band-pass filter..Iaddend..Iadd.
 12. An electronic timepiece according to claim 10, inwhich said temperature sensing filter circuit comprises a phase shiftingelement. .Iaddend..Iadd.
 13. An electronic timepiece according to claim9, in which said temperature sensing oscillator comprises a band-cutfilter and an amplifier connected thereto. .Iaddend..Iadd.
 14. Anelectronic timepiece according to claim 9, in which said temperaturesensing oscillator comprises a resistor and a condenser connectedthereto. .Iaddend..Iadd.
 15. An electronic timepiece according to claim9, in which said temperature sensing oscillator comprises a mechanicalresonance element having an electro-mechanical transducing function, andan amplifier connected to said mechanical resonance element..Iaddend..Iadd.
 16. An electronic timepiece according to claim 15, inwhich said mechanical resonance element comprises a ceramic resonator..Iaddend..Iadd.
 17. An electronic timepiece according to claim 15, inwhich said mechanical resonance element comprises a quartz crystalresonator. .Iaddend..Iadd.
 18. An electronic timepiece according toclaim 8, in which said compensating means comprises an algebraicalfrequency adding circuit for algebraically adding the frequency of saidoscillator circuit to the frequency of said time base signal. .Iaddend..Iadd.
 19. An electronic timepiece according to claim 18, in which saidfrequency adding circuit comprises an EX-OR gate. .Iaddend..Iadd.
 20. Anelectronic timepiece according to claim 17, in which said time basesignal generator comprises a quartz crystal controlled oscillator..Iaddend..Iadd.
 21. An electronic timepiece according to claim 9,further comprising a timing control unit for providing a timing controlsignal to control an oscillating operation of said temperature sensingoscillator so as to cause said temperature sensing oscillator tointermittently operate. .Iaddend..Iadd.
 22. An electronic timepieceaccording to claim 21, in which said temperature sensing oscillatorcomprises a gate circuit to control starting and stopping operations ofsaid temperature sensing oscillator in response to said timing controlsignal. .Iaddend..Iadd.
 23. An electronic timepiece according to claim22, further comprising a memory circuit for storing said temperaturesignal until a next temperature signal is stored. .Iaddend..Iadd.
 24. Anelectronic timepiece according to claim 9, in which said time basesignal generator and said temperature sensing oscillator comprise acommon reference vibrator element, and first and second oscillatorcircuits connected to said common reference vibrator element..Iaddend..Iadd.
 25. An electronic timepiece according to claim 9, inwhich said time base signal generator and said temperature sensingoscillator comprise vibrator elements, respectively, which are enclosedin a common casing. .Iaddend..Iadd.
 26. An electronic timepieceaccording to claim 8, in which said compensating signal generating meanscomprises a frequency difference detection circuit for detecting afrequency difference between said time base signal and said temperaturesignal and providing a frequency difference signal as said compensatingsignal. .Iaddend.